In one proposed vehicle, a sun gear, a carrier, and a ring gear of a planetary gear mechanism are respectively connected to a first motor, to an engine, and to a second motor and a drive shaft linked with drive wheels (see, for example, Japanese Patent Laid-Open Gazette No. H09-308012). The proposed vehicle sets a torque command required to output to the drive shaft according to a torque command setting map, which decreases the torque command with an increase in rotation speed of the drive shaft (vehicle speed), in order to ensure a substantially constant power level output to the drive shaft against the driver's depression amount of an accelerator pedal. The output power of the engine goes through torque conversion by the planetary gear mechanism and the first and the second motors. Such torque conversion enables a power equivalent to the torque command to be output to the drive shaft. The engine may be driven at any drive point that ensures output of the power equivalent to the torque command to the drive shaft. Driving the engine at a possible most efficient drive point enables the enhanced energy efficiency.